Part Number: AM3354
Other Parts Discussed in Thread: TPS65910,
Tool/software: Linux
hey guys
i'm working on AM3354 and i'm porting my u-boot-2011 to u-boot-2016 in processor sdk 03.02.00.05 on our own custom board.
I'm disguising as "AM335x GP EVM" since it has the most similar hardware compared to ours.
we have the same PMIC TPS65910 on i2C0 with the same address 0x2D.And we also have NAND flash...etc.
so far i'm able to boot the MLO and u-boot.
But somewhere in the middle the power of AM3354 seems to be lost and u-boot can not run any further because of the power loss.
Like this:
U-Boot SPL 2016.05 (Aug 27 2018 - 09:26:37)
Trying to boot from MMC1
reading args
spl_load_image_fat_os: error reading image args, err - -1
reading u-boot.img
reading u-boot.img
reading u-boot.img
reading u-boot.img
U-Boot 2016.05 (Aug 27 2018 - 09:26:37 +0800)
CPU : AM335X-GP rev 2.1
Model: TI AM335x EVM
Watchdog enabled
DRAM: 512 MiB
NAND: 0 MiB
MMC: OMAP SD/MMC: 0, OMAP SD/MMC: 1
reading uboot.env
** Unable to read "uboot.env" from mmc0:1 **
Using default environment
<ethaddr> not set. Validating first E-fuse MAC
Net: eth0: ethernet@4a100000
Warning: usb_ether MAC addresses don't match:
Address in SROM is de:ad:be:ef:00:01
Address in environment is 0c:b2:b7:ab:35:52
, eth1: usb_ether
Press SPACE to abort autoboot in 2 seconds
To this point the AM3354 lost its power and u-boot was not able to run further.So generally i suspect it's a PMIC issue?
There is a LED call "D17" on our board which is the indication of VAUX33 output of TPS65910.And i can clearly see that the LED is on for a second or two.Then went off.
The power loss phenomenon happens a lot but do not happen every single time.There are small chances that the power is not lost and u-boot is started normally.
The detailed model of the PMIC is TPS65910A3A1RSL
Here is the schematic of our core board regarding PMIC.
And the way it's connected to AM3354 is:
I checked the I2C0 waveform output .And it seems at least the AM3354 is indeed issueing I2C0 commands to 0x2D address.
am33xx_spl_board_init() in board\ti\am335x\board.c which contains a number of initial sequence for tps65910 is also done without exiting unexpectedly.
here:
the power up sequence works well in u-boot-2011.But the initialization part is closed source and packed in a library.So i can't see how the old u-boot-2011 got the PMIC properly initialized.
My guess would be that there're some differences between our own board (schematic or tps65910 model suffix? ) and the TI AM335x GP EVM?
That the init code for AM335x GP EVM won't work for us?
Can you guys tell me where to start debugging this? like measuring the voltage output or do something else.
Right now i really don't know where i can start from...
for your convenience i'm also attaching the schematic of "AM335x GP EVM"
thanks
Yan dong
